Losing to the same opponents last month started a run of three defeats in just four games, accounting for the nine-point gap that now exists between the Dons and Ronny Deila’s side with just three games left.
Some will insist things are not definitively settled but Aberdeen would need an 18-goal winning margin at Parkhead next Sunday to vindicate the most pedantic of mathematicians.
Instead the Dons are left pondering just how they squandered their best chance of winning the league since blowing it on the last day of the season at Ibrox back in 1991, especially given the form of several individuals in the team.
No fewer than four of them made the PFA team of the season announced earlier this week. Jonny Hayes led that quartet with an additional, and thoroughly deserved, nomination for player of the year.
The Republic of Ireland international also picked up three awards at his club’s annual dinner on Thursday, and the reasons why he could yet spend the summer at the European Championships were evident from the off yesterday.
His speed, skill and trickery in possession were certainly too much for Louis Lang to deal with on his return following six weeks out injured as the defender’s mistimed tackle on the winger allowed Kenny McLean to start what threatened to be a rout, from the penalty spot after just five minutes.
Hayes eventually rounded off this comprehensive victory with a stunning run and finish, dashing past Keiran Kennedy and substitute Ben Hall before clipping in his first goal since scoring in the home win against Celtic in February.
Niall McGinn, who is certain to be in the Northern Ireland squad for France, had claimed the second in 25 minutes, sending Shay Logan clear on the right with a sweeping pass then guiding an equally inviting return ball in from 14 yards.
A Motherwell team who had won six of their previous seven matches were made to look distinctly ordinary for long spells and there was an inevitability about what happened next, as soon as Adam Rooney sprung off the bench just before the break.
He replaced the injured Simon Church in 42 minutes and it took just 12 more for someone who remains the Premiership’s third-top scorer, despite ten weeks out with a torn muscle, to make it 20 goals for the campaign.
Andrew Considine’s header was clawed on to the bar by Connor Ripley and Rooney proved his instincts have not been blunted by inactivity as the Irishman pounced in typical style to ram in the rebound.
It might well be his last goal of the season though as Rooney was forced off with a recurrence of the problem late on but on a day when Aberdeen secured successive second-place finishes, Derek McInnes was left wondering what might have been had the striker avoided injury.
The Aberdeen manager said: “It’s good to make sure of second place again but the loss of Danny Ward back to Liverpool then Adam’s injury meant we didn’t look as secure or as threatening at both ends of the pitch.
“I brought Simon Church in to play with him so it was ironic that as Adam came on, he went off. Adam has been so vital to us since he signed, we have had an overreliance on him.”
Motherwell’s meagre consolation came in 64 minutes when Chris Cadden’s shot was deflected over his own goalkeeper by Ash Taylor but a bad afternoon got significantly worse near the end.
The Fir Park side’s captain Keith Lasley received a straight red card for a tackle on McLean, a decision that so incensed Mark McGhee’s assistant, Steve Robinson, that he was sent to the stand by referee Bobby Madden for comments made to fourth official Nick Walsh.
It was a situation McGhee saw coming, though, as he revealed: “I said to Steve Robinson we were going to sit and watch the game and not argue with anyone. We came with a smile on our faces but unfortunately the fourth official in particular had a different agenda.”